In flagranti

The phrase 'in flagranti' basically means 'caught in the act.' Like, if you catch someone getting it on with someone else, you've caught them in flagranti – red-handed, right in the middle of things. This saying originally comes from Latin, 'in crimine flagranti', which you could literally translate to 'while the crime is blazing.' Back in the day, it was mostly used for actual crimes. In English, we still say 'in flagrante delicto' for criminal stuff, which means 'the blazing crime.'

Over time, as sayings like this got more common in everyday talk, 'in flagranti' started being used for all sorts of situations. Like the example above, we often use 'in flagranti' when talking about cheating. So, if someone's in a relationship and gets caught live cheating, that's being caught in flagranti. It's also used when you stumble upon a secret fling or an office romance. Basically, it's for any kind of affair or sneaky business. But it's not just for love stuff – you might use 'in flagranti' for catching a thief in the act too.

There are a bunch of other ways to say the same thing, like 'catch someone unawares', 'bust in on them', 'turn up unannounced', 'snow in', 'take by surprise.'

So, 'in flagranti' and all these other phrases really play on that shock factor, often surprising everyone involved in an 'in flagranti' scene.